UltiSnips fdetect autocmd conflicts with --noplugin

[Lucas Hoffmann]

Bug: On startup with `vim --noplugin` (or `set noloadplugins` in some rc file) I get an Error:
> Error detected while processing FileType Auto commands for "*":
> E117: Unknown function: UltiSnips_FileTypeChanged

Problem: The file ftdetect/UltiSnips.vim (creating the autocmd) is loaded but not the file plugin/UltiSnips.vim which would define the function.

Possible solutions: I'm not familiar with UltiSnips code base so I can only guess: Either you could remove the code from fdetect, the comment at the top of the file states:
> " This has to be called before ftplugins are loaded. Therefore
> " it is here in ftdetect though it maybe shouldn't
Or you can change the relevant UltiSnips functions (or all UltiSnips functions) to be autoloading functions. I just tested it and it seems that autoload functions still work with --noplugin. I am not sure of any other consequences from using autoloading functions.

System:
1. Arch Linux, vim 7.4.135, not sure about UltiSnips version (there are no versions in the code), I installed UltiSnips with pacman and `pacman -Qi vim-ultisnips` reports "Version: 2.2-1".
2. Mac OS X 10.9, vim 7.4.52, UltiSnips installed with Vundle, commit f6b197e18ee34c0d1f8f2d9f787e49829aa4431b of the official github repository

[SirVer (sirver)]

> Bug: On startup with `vim --noplugin` (or `set noloadplugins` in some rc file) I get an Error:

oh noooo - yet another obscure vim option that does not work as advertised. Why would someone install plugins and then not use them?

> Either you could remove the code from fdetect

Well, as you will have guessed the code is there for a reason - there is no other way to be loaded before all kinds of ftplugins but we need to be the first to be called when the filetype changes - so this hack is necessary to work around the limitations of Vim.

> Or you can change the relevant UltiSnips functions (or all UltiSnips functions) to be autoloading functions.

I did that now. I did not do it in the past because it felt moot - since we need to keep track of all CursorMoved commands anyways, the full plugin is always loaded. Now it is only loaded when you use the Cursor in insert mode - which will be always too. So autoload did not buy us anything for UltiSnips. However, moving the methods into autoload seems to have solved your --noplugin issues, check out https://github.com/SirVer/ultisnips/commit/82ca377aaff84eae9d0230e9941685901b226db4 and let me know if there are any problems.

[Lucas Hoffmann (l-m-h)]

Thank you for the fast reaction. It works!

> Why would someone install plugins and then not use them?
I'm using [vimpager](https://github.com/rkitover/vimpager) as my pager
and I set noloadplugins in my vimpagerrc. Other use cases might be
debugging or scripting (yes, some people use vim as an interpreter to
run scripts from command line).

Lucas

[SirVer (sirver)]

vim as pager is an odd idea indeed - Vim already aches and nearly breaks when I watch my log files at work and they are at most 200MB, using it as pager seems not the ideal use case. To each his own I guess :)

Glad that the fix did work for you.